Information-Centric Networking (ICN) is an emerging networking paradigm where named and routable data (content) is the focal point. Users send explicit requests (interests) which specify content by name, and the network handles routing these interests to some entity capable of satisfying them with the appropriate data response (producer). One key feature of ICN is opportunistic in-network content caching. This property facilitates efficient content distribution by reducing bandwidth consumption, lessening network congestion, and improving the content retrieval latency by users (consumers). Unfortunately, the same feature is also detrimental to privacy of content consumers and producers. Simple to implement, and difficult to detect, timing attacks can exploit ICN routers as “oracles” and allow an adversary to learn whether a nearby consumer recently requested certain content. The attack leverages a timing side channel that relies on router caches and is implemented by requesting a few packets from each piece of content being probed. Similarly, probing attacks that target content producers can be used to discover whether certain content has been recently distributed. After analyzing the scope and feasibility of such attacks, we propose and evaluate some efficient countermeasures that offer quantifiable privacy guarantees while retaining the benefits of ICN.

Content-Centric Networking (CCN), an instance of information-centric networking, is a candidate next-generation Internet architecture that emphasizes on content distribution by making it directly addressable and routable. By opportunistically caching content within the network, CCN appears to be well-suited for a large-scale content distribution and for meeting the needs of increasingly mobile and bandwidth-hungry applications that dominate today's Internet. To provide content authentication, CCN dictates that each content object must be digitally signed by its respective producer. All entities (consumers and routers) must, in principle, verify the content signature before processing it. However, in practice, this poses two challenges for routers: (1) overhead due to signature verification, key retrieval, and potential certificate chain traversal; and (2) lack of trust context, i.e., determining which public keys are trusted to verify the content signature. This renders signature verification impractical in routers, opening the door for the so-called content poisoning attacks. We study the root causes of the content poisoning attacks and reach the conclusion that meaningful mitigation of content poisoning is contingent upon a network-layer trust management architecture. We propose two approaches: deterministic and probabilistic, that allow routers to detect fake (aka “poisoned”) content objects. The usages of each approach depend on the location and role of routers in the network, as well as their computational capabilities.

Information-Centric Networking (ICN) is a recent paradigm that claims to mitigate some limitations of the current IP-based Internet architecture. The centerpiece of ICN is named and addressable content, rather than hosts or interfaces. Content-Centric Networking (CCN) is a prominent ICN instance that shares the fundamental architectural design with its equally popular academic sibling Named- Data Networking (NDN). CCN eschews source addresses and creates one-time virtual circuits for every content request (called an interest). As an interest is forwarded it creates state in intervening routers and the requested content back is delivered over the reverse path using that state. Although a stateful forwarding plane might be beneficial in terms of efficiency and resilience to certain types of attacks, this has not been decisively proven via realistic experiments. Since keeping per-interest state complicates router operations and makes the infrastructure susceptible to router state exhaustion attacks (e.g., there is currently no effective defense against Interest Flooding attacks), the value of the stateful forwarding plane in CCN should be re-examined. In this paper, we explore supposed benefits and various problems of the stateful forwarding plane. We then argue that its benefits are uncertain at best and it should not be a mandatory CCN feature. To this end, we propose a new stateless architecture for CCN that provides nearly all functionality of the stateful design without its headaches. We analyze performance and resource requirements of the proposed architecture via experiments.

Content-Centric Networking (CCN) is a recently proposed Internet paradigm that focuses on scalable, secure and efficient content distribution. The main abstraction is named and addressable content. A consumer requests desired named content by generating a so-called interest, which is then routed by the network towards an in-network cached copy, or the authoritative producer, of that content. Since all CCN content must be signed by its producer, consumers and routers can cryptographically verify its correctness, authenticity, and integrity. Thus, in principle, attacks that introduce fake (poisoned) content can be detected. However, verifying content signatures is optional for CCN routers, detection of fake content only implies presence of a malicious upstream entity. A major outstanding problem in CCN is how to react to such attacks, determine their source(s), and re-route interests accordingly. In this work, we construct a technique based on efficient per-hop packet integrity checks. Routers share secrets with neighboring routers and use them to verify and generate efficient per-hop packet authenticators. An on-path attacker that tampers with content in transit is quickly detected by downstream routers. Moreover, an on-path attacker that hijacks a namespace is discoverable. Our experimental assessment indicates that the proposed technique incurs very low per-packet overhead. Furthermore, since our approach is not CCN-specific, it can be applied to IP-based networks as well.

Content-Centric Networking (CCN) is a recent network paradigm designed to address some key limitations of the current IP-based Internet. One of its main features is innetwork content caching which allows requests for content to be served by routers. Despite the benefits of improved bandwidth utilization and lower latency of retrieving popular content, innetwork caching inhibits producers from collecting information about content that is requested and later served from network caches. Such information is often needed for accounting and popularity purposes. In this paper, we address accounting in CCN by varying the degree of consumer, router, and producer involvement. We also identify and analyze inherent performance and security tradeoffs. We show that fine-grained accounting is infeasible with router caches and without explicit application support. We then recommend accounting strategies that entail a few simple requirements for CCN architectures. Finally, we show, via experimental results, that network-layer CCN accounting is viable and incurs low overhead for all parties involved. approaches.

Content-Centric Networking (CCN) is a communication paradigm that emphasizes content distribution. Named-Data Networking (NDN) is an instantiation of CCN, a candidate Future Internet Architecture. NDN supports human-readable content naming and router-based content caching which lends itself to efficient, secure, and scalable content distribution. Because of NDN's fundamental requirement that each content object must be signed by its producer, fragmentation has been considered incompatible with NDN since it precludes authentication of individual content fragments by routers. The alternative is to perform hop-by-hop reassembly, which incurs prohibitive delays. In this paper, we show that secure and efficient content fragmentation is both possible and even advantageous in NDN and similar content-centric network architectures that involve signed content. We design a concrete technique that facilitates efficient and secure content fragmentation in NDN, discuss its security guarantees and assess performance. We also describe a prototype implementation and compare performance of cut-through with hop-by-hop fragmentation and reassembly.

Content-Centric Networking (CCN) is an alternative to host-centric networking exemplified by today's Internet. CCN emphasizes content distribution by making content directly addressable. Named-Data Networking (NDN) is an example of CCN being considered as a candidate next-generation Internet architecture. One key NDN feature is router-side content caching that optimizes bandwidth consumption, reduces congestion and provides fast fetching for popular content. Unfortunately, the same feature is also detrimental to privacy of both consumers and producers of content. As we show in this paper, simple and difficult-to-detect timing attacks can exploit NDN routers as "oracles" and allow the adversary to learn whether a nearby consumer recently requested certain content. Similarly, probing attacks that target adjacent content producers can be used to discover whether certain content has been recently fetched. After analyzing the scope and feasibility of such attacks, we propose and evaluate some efficient countermeasures that offer quantifiable privacy guarantees while retaining key features of NDN.

We present SinPack, a security protocol for preventing packet pollution attacks in network-coded content distribution networks. SinPack employs a homomorphically-addressable Bloom filter data structure to enforce the integrity of network-coded packets all the way from source to destination. Using a Bloom filter "amortizes" the functionality of traditional cryptographic integrity verification constructs (Message Authentication Codes, hash trees, digital signatures, etc) in a relatively small-sized data structure. This aids in reducing network traffic and, more significantly, allows the incremental integrity verification of out of order network packets. The novel homomorphic Bloom filter construction permits intermediate routers and destination end systems to verify the integrity of source packets even after being network-coded by routers. This methodology avoids the need to establish expensive and intricate trust relationships among the different network routers and ensures the authenticity of the integrity structures using a single source public-key operation. Moreover, SinPack not only allows the content downloader to immediately verify the integrity of coded packets, but also provides this capability to any intermediate router on the path to the destination. This helps in eliminating polluted packets in the network upstream closest to the source of attack and as a result contributes to a great reduction in bogus network traffic and hence sizeable energy savings.